| Structural highlights
Function
[PCNA_HUMAN] Auxiliary protein of DNA polymerase delta and is involved in the control of eukaryotic DNA replication by increasing the polymerase's processibility during elongation of the leading strand. Induces a robust stimulatory effect on the 3'-5' exonuclease and 3'-phosphodiesterase, but not apurinic-apyrimidinic (AP) endonuclease, APEX2 activities. Has to be loaded onto DNA in order to be able to stimulate APEX2. Plays a key role in DNA damage response (DDR) by being conveniently positioned at the replication fork to coordinate DNA replication with DNA repair and DNA damage tolerance pathways. Acts as a loading platform to recruit DDR proteins that allow completion of DNA replication after DNA damage and promote postreplication repair: Monoubiquitinated PCNA leads to recruitment of translesion (TLS) polymerases, while 'Lys-63'-linked polyubiquitination of PCNA is involved in error-free pathway and employs recombination mechanisms to synthesize across the lesion.[1] [2] [PAF15_HUMAN] PCNA-binding protein that acts as a regulator of DNA repair during DNA replication. Following DNA damage, the interaction with PCNA is disrupted, facilitating the interaction between monoubiquitinated PCNA and the translesion DNA synthesis DNA polymerase eta (POLH) at stalled replisomes, facilitating the bypass of replication-fork-blocking lesions. Also acts as a regulator of centrosome number.[3] [4]
Publication Abstract from PubMed
The intrinsically disordered protein p15(PAF) regulates DNA replication and repair by binding to the proliferating cell nuclear antigen (PCNA) sliding clamp. We present the structure of the human p15(PAF)-PCNA complex. Crystallography and NMR show the central PCNA-interacting protein motif (PIP-box) of p15(PAF) tightly bound to the front-face of PCNA. In contrast to other PCNA-interacting proteins, p15(PAF) also contacts the inside of, and passes through, the PCNA ring. The disordered p15(PAF) termini emerge at opposite faces of the ring, but remain protected from 20S proteasomal degradation. Both free and PCNA-bound p15(PAF) binds DNA mainly through its histone-like N-terminal tail, while PCNA does not, and a model of the ternary complex with DNA inside the PCNA ring is consistent with electron micrographs. We propose that p15(PAF) acts as a flexible drag that regulates PCNA sliding along the DNA and facilitates the switch from replicative to translesion synthesis polymerase binding.
Structure of p15(PAF)-PCNA complex and implications for clamp sliding during DNA replication and repair.,De Biasio A, de Opakua AI, Mortuza GB, Molina R, Cordeiro TN, Castillo F, Villate M, Merino N, Delgado S, Gil-Carton D, Luque I, Diercks T, Bernado P, Montoya G, Blanco FJ Nat Commun. 2015 Mar 12;6:6439. doi: 10.1038/ncomms7439. PMID:25762514[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Burkovics P, Hajdu I, Szukacsov V, Unk I, Haracska L. Role of PCNA-dependent stimulation of 3'-phosphodiesterase and 3'-5' exonuclease activities of human Ape2 in repair of oxidative DNA damage. Nucleic Acids Res. 2009 Jul;37(13):4247-55. doi: 10.1093/nar/gkp357. Epub 2009, May 13. PMID:19443450 doi:10.1093/nar/gkp357
- ↑ Motegi A, Liaw HJ, Lee KY, Roest HP, Maas A, Wu X, Moinova H, Markowitz SD, Ding H, Hoeijmakers JH, Myung K. Polyubiquitination of proliferating cell nuclear antigen by HLTF and SHPRH prevents genomic instability from stalled replication forks. Proc Natl Acad Sci U S A. 2008 Aug 26;105(34):12411-6. Epub 2008 Aug 21. PMID:18719106 doi:0805685105
- ↑ Kais Z, Barsky SH, Mathsyaraja H, Zha A, Ransburgh DJ, He G, Pilarski RT, Shapiro CL, Huang K, Parvin JD. KIAA0101 interacts with BRCA1 and regulates centrosome number. Mol Cancer Res. 2011 Aug;9(8):1091-9. doi: 10.1158/1541-7786.MCR-10-0503. Epub, 2011 Jun 14. PMID:21673012 doi:http://dx.doi.org/10.1158/1541-7786.MCR-10-0503
- ↑ Povlsen LK, Beli P, Wagner SA, Poulsen SL, Sylvestersen KB, Poulsen JW, Nielsen ML, Bekker-Jensen S, Mailand N, Choudhary C. Systems-wide analysis of ubiquitylation dynamics reveals a key role for PAF15 ubiquitylation in DNA-damage bypass. Nat Cell Biol. 2012 Oct;14(10):1089-98. doi: 10.1038/ncb2579. Epub 2012 Sep 23. PMID:23000965 doi:http://dx.doi.org/10.1038/ncb2579
- ↑ De Biasio A, de Opakua AI, Mortuza GB, Molina R, Cordeiro TN, Castillo F, Villate M, Merino N, Delgado S, Gil-Carton D, Luque I, Diercks T, Bernado P, Montoya G, Blanco FJ. Structure of p15(PAF)-PCNA complex and implications for clamp sliding during DNA replication and repair. Nat Commun. 2015 Mar 12;6:6439. doi: 10.1038/ncomms7439. PMID:25762514 doi:http://dx.doi.org/10.1038/ncomms7439
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